The present invention relates to integrated circuit packages and more particularly to carriers for packaging, handling, and testing high-lead density electronic integrated circuit packages, such as an 180-lead gate array package.
Electronic integrated circuit (IC) packages, such as large scale integration (LSI) circuits, very large scale integration (VLSI) circuits, very high speed integrated circuits (VHSIC), and gate array circuits, are typically constructed with a large number of electrical leads. The leads eminate out from the body of the integrated circuit and are typically connected by a soldering process to a larger electronic unit, such as a wiring board or a printed circuit board. The printed circuit board is used to electrically connect several integrated circuits to cooperate in functioning together. Such a printed circuit board is installed in a unit of some electronics device, such as a radio, television, or radar system.
The complex configuration of electronics in modern integrated circuits results in a great number of electrical leads eminating from such circuits. In particular, a 180-lead gate array electronics package is an industry standard. The package is typically one and one-half inch on two sides and one inch on the other sides with as many as fifty-four leads eminating from each of two sides of the integrated circuit and as many as thirty-six leads eminating from each of the other two sides of the package. This results in a very high-lead density configuration, with lead spacings on the order of 0.030 inch centers.
In order to protect the integrated circuit packages from damage in handling and installing onto printed circuit boards, a protective device for the circuit package is required. Such device is intended to protect both the body of the integrated circuit from damage and the leads eminating from the body from breakage.
Moreover, in order to electrically test the integrated circuit requires placement of the circuit in cooperation with a performance board. Testing the circuit in as convenient manner possible prior to placing the circuit permanently on the printed circuit board is essential in order to avoid use of faulty integrated circuits.
One prior art approach to providing such lead protection for integrated circuit packages uses carriers having a separate groove or "nest" for each lead. Hughes Aircraft Company Part No. 821637 exemplifies a 42-lead package carrier and Hughes Aircraft Company Part No. 821638 exemplifies a 28-lead package carrier. These are one-piece construction integrated circuit carriers containing separate grooves or "nests" for each lead to rest in. With the current designs for high-lead density integrated circuits, and corresponding close lead spacings center-to-center (e.g., 0.030 inches, and to the extreme of 0.025 inches), carriers with separate grooves for each lead cannot be produced nor effectively utilized without major difficulties. Manufacture of carriers with high-density grooves is extremely impractical and costly, because the groove spacing is required to be extremely close. Devices in use also cause brittle electrical-wire leads to break or bend.
Furthermore, one-piece construction carriers for integrated circuit packages presently in use do not lend themselves to the testing of high-lead density packages.